# Day 7

3:02 P.M.

Block 6  (Physics 1,2)

One of the great things about not knowing what I am supposed to be doing, is that I get to model how I figure out what to do for my students. Case in point is this spaghetti bridge lab that we did in class. It took me a couple of runs to figure out what we were doing. I wanted this lab to be some crazy measurement of tensile strength, and depression of spaghetti. What I realized last night is that this is a lab for high school students new to the modeling method of physics.

All they had to do was figure out how many marbles break a number of strands of spaghetti.

It’s a simple linear graph.

(Whew!)

Thus with my last block it went very quickly. and they got very nice data that made sense.

In fact near the end of class, a couple of my students went on their device and started watching some videos. I was really excited because one of them I was able to turn into a 3-Act math problem

This got me thinking about how I can leverage student silliness into classroom results

Block 1 (AP Physics C)

AP Physics lends itself to direct instruction on some days. I wanted students to do a quick 3-Act problem based on the video above. I had them do about 10 MC problems over 15 minutes. I will grade those next week. What made me happy is that students noticed these problems were easier because they were similar to the mini-lab challenge we did the day before. It seems they are able to apply hands on knowledge to book problems, which is reassuring because that doesn’t always happen.

I then wanted to have students review Newton’s first law, talk about centripetal acceleration and have them try to figure out the slowest rate the wheel could spin and have the hamster “flip” (as the YouTube poster calls it)

I had the students write out Newton’s First law on whiteboards, and my favorite version was: “wanna keep on doin’ watcha doin'”.

We clarified this of course and from this we got into the idea that ANY deviation from constant velocity (magnitude OR direction) is acceleration.

I had students draw a free body diagram of the hamster at the bottom of the wheel.

Naturally some of them wanted to add an extra “centripetal” force. Thank goodness students were able to remember that when one throws a ball the only force acting after it is thrown is gravity (neglecting air resistance). We were able to draw the connection that the EFFECT of a net force can be centripetal acceleration.

This was  a great way to end the week with AP Physics.

Block 2  (Physics 1,2)

I had my first glitch with BYOD. My students had all their data from the spaghetti bridge lab, but given the sheer number of devices I had them graph it by hand on whiteboards after unsuccessfully trying to get them to figure out a way on their own.

This was helpful because we were at least able to create a need to know. Drawing points on a plot and eyeballing the best line can be helpful because I can challenge students and ask them how they “really” know that their line is the best-fit line.

I will find a few videos and instructions to get various students graphing and we will finish up next week.